[HASEL-UZH#4] Added fallback example

typescript/README.md

@@ -34,7 +34,33 @@ Not tested on Linux
 
 ## Known Issues
 
-- There is a [bug](https://stackoverflow.com/questions/2969110/cgeventtapcreate-breaks-down-mysteriously-with-key-down-events#2971217) on macOS that removes event listeners from time to time. [uiohook-napi](https://github.com/SnosMe/uiohook-napi) crashes when this happens (when used with Electron). This issue was [reported](https://github.com/SnosMe/uiohook-napi/pull/5), but it doesn't look like it will be fixed in the near future. To circumvent this issue, we created a [fork](https://github.com/HASEL-UZH/uiohook-napi). With the fork, the application no longer crashes but a restart of the tracker is required to reestablish the event listeners. This functionality has to be provided by the client application! As a reference, you could have a look at the [fallback](https://github.com/HASEL-UZH/PA.FlowTeams/commit/cef8c28eed34c82f37aa0f8e34f9f3b520ca9f66) created in the FlowTeams project.
+- There is a [bug](https://stackoverflow.com/questions/2969110/cgeventtapcreate-breaks-down-mysteriously-with-key-down-events#2971217) on macOS that removes event listeners from time to time. [uiohook-napi](https://github.com/SnosMe/uiohook-napi) crashes when this happens (when used with Electron). This issue was [reported](https://github.com/SnosMe/uiohook-napi/pull/5), but it doesn't look like it will be fixed in the near future. To circumvent this issue, we created a [fork](https://github.com/HASEL-UZH/uiohook-napi). With the fork, the application no longer crashes but a restart of the tracker is required to reestablish the event listeners. This functionality has to be provided by the client application! As a reference, you could have a look at the [fallback](https://github.com/HASEL-UZH/PA.FlowTeams/commit/cef8c28eed34c82f37aa0f8e34f9f3b520ca9f66) created in the FlowTeams project. There, the following code was added:
+```
+  // check if tracker is still running (issue of io-library that only occurs on Mac)
+  // restart the tracker when no input is detected but active window changed
+  const msPerMinute = 60000;
+  const startTime = new Date(Date.now() - 3 * msPerMinute);
+  if (
+    isMac &&
+    (calculatedFlowStatus.flowStatus === FlowStatus.AVAILABLE ||
+      calculatedFlowStatus.flowStatus === FlowStatus.AWAY)
+  ) {
+    const activeIOCount: number =
+      await UserInputAggregate.countActiveIntervals(startTime);
+    const activeWindowCount: number = await ActiveWindow.countActivity(
+      startTime
+    );
+    if (activeIOCount === 0 && activeWindowCount !== 0) {
+      console.error(
+        "[FlowTeams] No input detected for 3 minutes but detected window activity. Restart input tracker to resolve possible issue."
+      );
+      await this.pauseTrackers();
+      await this.resumeTrackers();
+    }
+  }
+```
+In words, if in the last three minutes no input was detected (`activeIOCount`), but window activity was still detected (`activeWindowCount` - [active-win](https://www.npmjs.com/package/active-win) is used for this) then restart the tracker.
+
   - Read more about it in this [issue](https://github.com/HASEL-UZH/PA.UserInputTracker/issues/4).
 
 ## Thanks